A diet rich in walnuts favourably influences plasma fatty acid profile in moderately hyperlipidaemic subjects.
OBJECTIVE
To compare two low fat diets one rich in walnuts on parameters of lipid metabolism in a group of hyperlipidaemic subjects.


METHODS
A randomised cross over study.


METHODS
Department of Human Nutrition, University of Otago, Dunedin, New Zealand


METHODS
Twenty one men with mean (s.d.) levels of total and LDL cholesterol of 6.58 (0.60) and 4.63 (0.58) respectively.


METHODS
For two periods of four weeks subjects were asked to consume two low fat diets (fat 30% total energy), one containing, on average, 78 g/d walnuts. Walnuts obtained through Lincoln University and the Walnut Growers Group (South Canterbury).


RESULTS
Participants reported a higher total fat intake on the walnut diet (38% compared with 30% on the low fat diet P < 0.01) The most consistent change in fatty acid profile of triacylglycerol, phospholipid and cholesterol ester on the walnut diet was a significant (P < 0.01) increase in linoleic acid. Triacylglycerol linolenate also increased significantly (P < 0.01). Total and LDL cholesterol were lower on both experimental diets than at baseline, 0.25 mmol/l and 0.36 mmol/l respectively on the walnut diet and 0.13 mmol/l and 0.20 mmol/l respectively on the low fat diet. High density lipoprotein cholesterol was higher on both the walnut and low fat diets when compared to baseline (0.15 mmol/l and 0.12 mmol/l, respectively). When comparing the walnut and low fat diets only apo B was significantly lower (P < 0.05) on the walnut diet.


CONCLUSIONS
Despite an unintended increase in the total fat intake on the walnut diet, fatty acid profile of the major lipid fractions showed changes which might be expected to reduce risk of cardiovascular disease. The reduction of apolipoprotein B suggests a reduction in lipoprotein mediated risk, the relatively low myristic acid content of both diets perhaps explaining the absence of more extensive differences in lipoprotein levels on the two diets.
Chisholm
A
A
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Mann
J
J
Skeaff
M
M
Frampton
C
C
Sutherland
W
W
Duncan
A
A
Tiszavari
S
S
D000328:Adult; D002784:Cholesterol / Q000097:blood; D002788:Cholesterol Esters / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage*; D005227:Fatty Acids / Q000097:blood*; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000178:diet therapy*; D019787:Linoleic Acid / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009754:Nuts; D010743:Phospholipids / Q000097:blood; D014280:Triglycerides / Q000097:blood; D017962:alpha-Linolenic Acid / Q000008:administration & dosage
D002788:Cholesterol Esters; D008078:Cholesterol, LDL; D004041:Dietary Fats; D005227:Fatty Acids; D010743:Phospholipids; D014280:Triglycerides; D017962:alpha-Linolenic Acid; D002784:Cholesterol; D019787:Linoleic Acid